The present invention relates to a valve apparatus for a hermetic compressor, and more particularly, to a valve apparatus for a hermetic compressor capable of improving the discharging efficiency of a refrigerant, and reducing abrasion and noise generated by the valve apparatus.
Generally, a hermetic compressor includes a reciprocal compressor, a linear compressor, and a rotary compressor. Most of the compressors have a valve apparatus for preventing a refrigerant from being drawn into a compressing chamber.
The valve apparatus of a conventional reciprocal compressor associated with hermetic compressors is shown in FIG. 1. As shown in FIG. 1, the valve apparatus comprises a valve plate 10 having a refrigerant discharging hole 10a being disposed between a cylinder block (not shown) and a cylinder head (not shown), a discharging valve 11 disposed at the valve plate 10, a stopper 13, and a keeper 15.
One end of the discharging valve 11 and the stopper 13 are connected to an outer surface of the valve plate 10. The stopper 13 has a longer length than that of the discharging valve 11. The keeper 15 is placed above the stopper 13 and is protuberant upwardly. A free end of the stopper 13 contacts a bend portion of the keeper 15, particularly when the compressor is operating.
In the above construction, a refrigerant is compressed by a piston (not shown) and discharged through the discharging hole 10a. At this time, the discharging valve 11 is pressed against the stopper 13 as the discharging valve 11 is opened by the pressure of the discharging refrigerant. The stopper 13 is repeatedly pressed against the keeper 15 as the center of the stopper 13 is bent by the discharging pressure.
Additionally, the discharging force and noise can be reduced by reducing the movement of the discharging valve 11, as the free end of the stopper 13 is stopped by the bent portion of the keeper 15. In other words, when the compressor operates, the level of the discharging force and the noise of the valve apparatus can be controlled by adjusting the height of the keeper 15 and the size of the refrigerant discharging hole 10a. 
However, the keeper 15 and the discharging valve 11 are fixed in the above valve apparatus, and the height of the keeper 15 and the size of the discharging valve 11 cannot be adjusted. This makes it difficult to find an appropriate point to allow the discharging valve 11 to be opened in accordance with the discharging pressure of the refrigerant.
Moreover, as the size of the refrigerant discharging hole 10a formed at the valve plate 10 is varied in accordance with the amount of the refrigerant, a valve plate 10 having a standardized refrigerant discharging hole 10a size cannot be manufactured. Accordingly, valve plates 10 having various dimension and specifications must be manufactured to meet each particular situation.
The present invention has been made to overcome the above-mentioned problems of the related art. Accordingly, it is an object of the present invention to provide a valve apparatus of a hermetic compressor having an improved structure for freely adjusting a height of the valve in accordance with a discharging pressure and discharging amount of refrigerant.
The valve apparatus of the hermetic compressor according to the present invention comprises a valve plate having a refrigerant discharging hole for discharging a refrigerant, a discharging valve having one end fixed at the valve plate and another end for opening and closing the refrigerant discharging hole, a stopper having one end fixed at the valve plate in order to support the discharging valve, a keeper fixed at the valve plate and disposed at an upper part of the stopper at a predetermined distance, a first shock absorbing means disposed at the keeper for buffering the opening and closing of the stopper, and a second shock absorbing means disposed at the keeper in order to move up and down. The second shock absorbing means is for buffering the opening and closing of the stopper together with the first shock absorbing means.
In the preferred embodiment, the first shock absorbing means includes a spring disposed at a lower part of the keeper and a shock absorbing plate supported at the spring and connected with the stopper in order to buffer the stopper. The second shock absorbing means includes a cylinder disposed at the keeper and a piston having one end connected with the first shock absorbing means and another end that reciprocates in the cylinder. Additionally, in the preferred embodiment the cylinder is an air cylinder.